1. Field of the Invention
The present invention relates to a patch antenna synchronously generating a circularly polarized wave and a linearly polarized wave and a generating method thereof.
2. Description of the Related Art
In general, a patch antenna includes a dielectric plate. One surface of the dielectric plate is used as a ground plate, and another surface thereof configures a circuit as a strip line. Since the patch antenna can be manufactured by a printed board, it is advantageous in that it is easily manufactured, suitable for mass production, and firm, and has a low height. Because the antenna may easily engage with integrated circuit (IC) devices, it is widely used in small devices of millimeter band such as a portable phone.
The patch antenna can be divided into a linearly polarized wave antenna and a circularly polarized wave antenna.
FIG. 1 is a graph illustrating a moving direction of a linearly polarized wave. FIG. 2 is a graph illustrating a moving direction of a circularly polarized wave.
Here, the linearly polarized wave includes a vertical polarized wave having an electric field perpendicular to the ground and a horizontal polarized wave having an electric field horizontal to the ground, A circularly polarized wave is a polarized wave that has an electric field rotating in a string shape and moving along an axis.
When a circularly polarized antenna generating a circularly polarized wave communicates with a linear polarized antenna generating a linearly polarized wave, −3 dB loss theoretically occurs between the two antennas. Therefore, there is a need for a patch antenna synchronously generating a circularly polarized wave and a linearly polarized wave to communicate with a circularly polarized antenna or a linearly polarized antenna without loss.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.